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The conventional preparation of SnNb2O6 invariably involves complex and laborious steps, which unavoidably introduces defect into the host lattice and also increases the reaction period and costs, resulting in undesired recombination of photo-generated electron–hole pairs. For the first time in this work, we manage to synthesize single-crystalline two-dimensional (2D) SnNb2O6 nanosheets with ultrathin structure through a facile one-step hydrothermal method. Comparative studies were explored to analyze the structure and phase evolution during the preparation course. The synthesized 2D structure demonstrated a narrower band gap of 2.09 eV and specific surface area of 76.1 m2 g−1, which exhibited significantly extended visible-light-responsive range and larger surface area by contrast with the state-of-the-art reports, resulting in excellent visible-light-driven photoactivity towards H2 production and water purification as well. Additionally, further enhanced photocatalytic performance was achieved by the incorporation of Pt as co-catalyst to indirectly indicate the advantage of the SnNb2O6 nanosheets in this method over other reported counterparts. It was found that, a very small amount of Pt loaded on the surface of SnNb2O6 nanosheets would contribute to remarkably higher activity than pure SnNb2O6 nanosheets and exhibit superior stability as well. Moreover, a deep insight into the underlying photocatalytic mechanism was proposed. This work sheds light on a new facile way to fabricate high-performance photocatalytic materials and provided new opportunities for solar-energy conversion. [ABSTRACT FROM AUTHOR]

Bi 2 MoO 6 :Er3+/0.03Yb3+@Bi y flower-like microspheres were designed to promote the visible light driven photocatalytic activity of Bi 2 MoO 6 flower-like microspheres by simultaneously utilizing the doping and SPR engineering. [Display omitted] • Bi 2 MoO 6 :Er3+/ x Yb3+ flower-like microspheres with intense UC emissions were prepared. • Compared with Bi 2 MoO 6 , these sampled doped with Er3+ and Yb3+ can degrade TC more efficiently. • Due to SPR effect of Bi, photocatalytic activities of studied samples are further improved. • The involved photocatalytic mechanism is contributed by ·O 2 –, ·OH and h+ active species. • Treated TC by resultant flower-like microspheres is nontoxicity to plant growth. Series of Er3+/Yb3+-codoped Bi 2 MoO 6 (Bi 2 MoO 6 :Er3+/ x Yb3+) and Bi 2 MoO 6 :Er3+/0.03Yb3+@Bi y flower-like microspheres were designed to improve the visible light driven photocatalytic activities of Bi 2 MoO 6 flower-like microspheres. The electronic structure of Bi 2 MoO 6 host was analyzed through the first-principle density functional theory. Excited at 980 nm, glaring UC emissions are gained in Bi 2 MoO 6 :Er3+/ x Yb3+ compound and their strongest intensities are obtained at × = 0.05, where the corresponding mechanism is a two-photon absorption process. Through studying the tetracycline (TC) degradation under visible light irradiation, the photocatalytic activities of final products were explored. Compared with Bi 2 MoO 6 flower-like microspheres, these samples doped with Er3+ and Yb3+ can remove TC more efficiently and the optimal performance is achieved when a = 0.03. Furthermore, via using the surface plasmon resonance (SPR) effect caused by metallic Bi, the photocatalytic activities of the designed samples were further manipulated, where the TC removal rate of Bi 2 MoO 6 :Er3+/0.03Yb3+@Bi 0.10 flower-like microspheres is 91.0% after irradiating by visible light for 24 min. Moreover, the included photocatalytic processes are triggered by ·O 2 –, ·OH and h+ active species. Additionally, the TC solution treated by the designed photocatalysts shows non-toxicity to plants. These results imply that Bi 2 MoO 6 :Er3+/0.03Yb3+@Bi y flower-like microspheres are potential visible light driven photocatalysts for wastewater purification and our finding may also provide guidelines for tailoring of the photocatalytic activities of semiconductors by synergistic effect of doping and SPR engineering. [ABSTRACT FROM AUTHOR]

We report herein a means of transforming TiO 2 nanotube arrays (TNAs) from an amorphous state to an anatase crystal state (denoted as ∗ TNAs), and present a single-step synthetic route for preparing CdS quantum dots (CdS QDs) as well as reduced graphene oxide (rGO) through gamma-ray irradiation. The as-prepared ∗ TNAs, CdS QDs, and rGO, which had all been subjected to gamma-ray irradiation, were then assembled together to produce the desired heterojunction (denoted as CdS QDs/rGO- ∗ TNAs). X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), ultraviolet/visible diffuse-reflectance spectroscopy (UV/Vis DRS), Fourier-transform infrared spectroscopy (FTIR), micro-Raman spectrometry (RS), atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS) have been applied to characterize the appearance and performance of this photocatalyst. The photocatalytic activity of CdS QDs/rGO- ∗ TNAs towards ethylene degradation has been measured by placing it in a simulated cold-storage environment, the temperature and humidity of which were set at about 3 ± 1 °C and 75–90%, respectively. The results showed that the rate constant ( K ) of ethylene degradation could reach up to 1.07 × 10 −3  min −1 with CdS QDs/rGO- ∗ TNAs, as compared to 2.30 × 10 −4  min −1 with ∗ TNAs and 6.25 × 10 −4  min −1 with CdS QDs- ∗ TNAs, indicating that the constructed CdS QDs/rGO- ∗ TNAs constitutes a promising photocatalyst for ethylene removal in a cold storage environment. [ABSTRACT FROM AUTHOR]

Photocatalytic activities of three composites, namely nickel foam/Ag-TiO2, nickel foam/Ag-ZnO, and nickel foam/Ag-WO3, were evaluated for toluene degradation in a home-made cuboid photoreactor. Scanning electron microscopy and energy dispersive spectrometry were employed to characterize these photocatalysts. The photodegradation effects of the three photocatalysts peaked under 60% relative humidity, with nickel foam/Ag-TiO2exhibiting the highest rate of photocatalytic toluene degradation. Controlling humidity could enhance the photocatalytic toluene degradation activities of the three composites, which are significantly affected by a wider band gap. In this study, a dynamic model was proposed and analyzed according to the time-dependent photodegradation of toluene. [ABSTRACT FROM AUTHOR]

• Flower-like ZnIn 2 S 4 coupled with black phosphorus (BP) as efficient photocatalyst. • BP and photo-deposited Pt played a synergistic role in enhancing photocatalytic H 2 evolution. • 0.5%Pt/0.5%BP/ZnIn 2 S 4 showed the best H 2 production efficiency at 1278 μmol/g/h. • Superior recycling stability of more than 4 cycles for solar hydrogen evolution. To make persistent efforts at enhancing hydrogen evolution driven by solar energy, this work, for the first time, had introduced flower-like ZnIn 2 S 4 coupled with black phosphorus (BP) as efficient photocatalyst for hydrogen evolution with photo-deposited Pt assisted under visible light irradiation. The hydrogen evolution efficiency of BP, ZnIn 2 S 4 , 0.5%BP/ZnIn 2 S 4 , 0.5%Pt/BP, 0.5%Pt/ZnIn 2 S 4 and 0.5%Pt/0.5%BP/ZnIn 2 S 4 photocatalysts were successively conducted and results showed that both BP and Pt played an important role in enhancing the photocatalytic hydrogen evolution rate. Therefore, the ternary 0.5%Pt/0.5%BP/ZnIn 2 S 4 composite exhibited the strongest hydrogen production efficiency at 1278 μmol/g/h, about 10 times higher than that of pristine ZnIn 2 S 4 (131 μmol/g/h) and represented a highly stable characteristic after suffering four recycles. The promoting hydrogen evolution of ternary photocatalyst could be ascribed to the unique bandgap and larger two-dimensional plane structure of BP, which provided abundant landing sites for the anchor of flower-like ZnIn 2 S 4 , thus leading to a well-inhibited recombination and efficient separation of photogenerated electrons and hole pairs between ZnIn 2 S 4 and BP. The remarkable photocatalytic hydrogen evolution performance and prominent stability all indicated that 0.5%Pt/0.5%BP/ZnIn 2 S 4 was a promising photocatalyst candidate for solar hydrogen production. [ABSTRACT FROM AUTHOR]

Developing high-efficiency and low-cost photocatalysis are of important significance for large-scale organic waste disposal technologies. Here, a versatile and simple solvothermal-sintering route is proposed to construct WO 3 /TiO 2 heterojunction for catalytic oxidation of origin dyes under visible light irradiation. Tightly bonded bimetal centers and well-designed heterojunction lead to significantly reduced band gap of the photocatalysis. Furthermore, significantly enhanced photocatalytic activity are achieved for degrading various organic dyes under visible light. In particular, the degradation rate of RhB with the heterojunction reaches 95.31% under visible light for 80 min, which is considerably higher than that of 34.81% with TiO 2. Besides, WO 3 /TiO 2 heterojunction still maintains excellent photocatalytic activity after three cycles of degradation. This work proposes a simple, low-cost but effective route to fabricate WO 3 /TiO 2 heterojunction, which can be used for large-scale organic wastewater disposals across industrial circles. [Display omitted] • A simple, low-cost but effective route to fabricate WO 3 /TiO 2 heterojunction. • WO 3 /TiO 2 heterojunction leads to significantly enhanced photocatalytic activity. • WO 3 /TiO 2 heterojunction contributes to large-scale organic wastewater disposals. [ABSTRACT FROM AUTHOR]